The field of the disclosure relates generally to soil treatments, and more particularly to methods and apparatus for applying soil treatments (e.g., pesticides) below the ground surface using a handheld application tool that in certain modes of operation does not disturb the soil surface before the soil treatment is injected.
The insertion of soil treatments into the soil near buildings has been used to prevent the infestation of insects or other pests. Without treatment, these pests can be become a significant nuisance or hazard to a building owner or its occupants. Such pests are known to attack the structure of buildings and may infiltrate the building causing other problems for its occupants.
At least one known method of soil treatment includes an application of pesticides, fertilizers, or other soil treatments by direct placement into the soil under and around structures, around or near ornamental plantings, poles, fences, decks, or other wooden elements. This direct placement method includes digging, trenching and/or rodding (i.e., forcing an application device into the soil), and then directly placing the soil treatment into the dug out area of the trench. This known method can cause damage to vegetation, disrupt landscaping, and greatly impact or diminish the aesthetic beauty and value of the treated area until either the plants recover or new plantings are installed.
For example, in some common termite treatments direct placement of a termiticide into the soil around structures involves the digging of a trench approximately 4 to 6 inches wide by 6 inches deep into which a termiticide composition is applied at a rate of 4 gallons per 10 linear feet of trench per foot of depth. In addition to the application of the soil treatment to the trench, soil treatment may also be dispensed into the ground through the use of a rod injection tool, which is plunged down into the ground generally to a depth that is approximately to the top of a footer (i.e., a part of the building's foundation). For a typical structure having a perimeter of 200 linear feet, the time to prepare, dig, inject, and finish the application of soil treatment requires at least 4 to 6 hours depending on the type of soil and whether the application is conducted by a pair of or a single technician(s).
Another known method of soil treatment includes the direct insertion of a tool down into the ground and delivering the pesticides, fertilizers, or other soil treatments into the ground. Applying the soil treatments below the surface of the soil has been used as a way of limiting the wash off of the treatments. Typical devices for implementing such soil treatments have utilized needles or other mechanical devices, creating both a passageway into the soil and through which the treatments are applied to the subsurface area. These devices have the obvious limitation that they create holes in the soil, which may be unsightly, or create other adverse concerns, such as unwanted soil compaction adjacent the insertion sights, as well as require the creation of the hole using mechanical forces. Moreover, devices that are pushed into the ground can become plugged with soil or other debris which requires disassembly of the application tool for cleaning. Another disadvantage to devices that are pushed into the ground is that they can become contaminated with soil borne pathogens or other contaminates that can potentially be transferred to the next injection site.
The use of high pressure flows as a method of effectively injecting materials below the soil surface has been described before, such as in U.S. Pat. No. 5,370,069 to Monroe, titled Apparatus and Method for Aerating and/or Introducing Particulate Matter into a Ground Surface. These methods use high pressure jets of a fluid, such as air or water that entrain the soil treatment agent, whether the soil treatment agent is in solution with the fluid, or a granular material carried with the fluid. The high pressure jet can form a small hole in the surface into which the material is being placed, or cause the material to be absorbed by the surface in a rapid fashion, such that soil disturbance is minimal. One benefit of the use of a pressure jet is that no mechanical effort is required to create a passageway as a predicate for the soil treatment material to be placed below the surface of the soil. Nor is any other disturbance of the soil required, such as placing a tool directly down below the ground surface.
While devices such as that disclosed in Monroe are effective at placing soil treatment materials below the surface, they are designed to distribute such materials both a short distance below the soil surface and over a large open space area, where the size of the equipment is not a limitation. These known devices are not suitable for strategically injecting soil treatments to greater depths within the soil under and around structures, ornamental plantings, poles, fences, decks and other wood elements where treatments relating particularly to treatments against insects infestation are common.
Accordingly, a handheld high pressure application tool for applying soil treatments (e.g., termiticide or other pesticide) beneath the surface of the ground adjacent a structure is needed. Such a handheld tool would permit an operator to strategically position the tool around a structure such as a house, a deck, any landscaping that may be near the house and/or deck, around utility poles, and around plants. The tool could include multiple nozzles for applying a predetermined amount of soil treatment at a controlled pressure for injecting the soil treatment down to a desired predetermined depth. This would allow for precision applications where the area of application is carefully controlled.
In some applications, however, the type of soil (e.g., hard, compacted, etc.) or other obstructions (e.g., a concrete patio, walkway, etc.) may prevent an operator from treating certain areas with a high pressure application tool. Thus, a system that can operate in different modes, such as a high pressure mode and a low pressure mode (for use in applying the pesticide to areas in which a high pressure application is not feasible) is needed.